David L. Trudeau disclosed an Umbrella having the appearance of a conventional unbrella extended to open in the form of a baseball hat in his U.S. Pat. No. 4,597,400, which however may not fully shield a user's shoulders because the lower spreaders 62, 64 pivotally mounted on a sleeve 56 may obstruct a user's head and shoulders, unable to poke into a bell-shaped crown 12.
By modifying the Trudeau's umbrella in view of Caldwell's U.S. Pat. No. 100,012 for poking a users head into the bell-shaped crown or dome, the umbrella will not be foldable with respect to an illustration as shown in FIG. 2 which is inferentially expected from FIG. 1.
As shown in FIG. 1, the Caldwell's umbrella of U.S. Pat. No. 100,012 may be folded by a parallelogram defined by links B, F, E, C and may be extended to have a pose of a tilting end bow F which would be vulnerable to receive a strong wind force especially when walking in a storm, resulting in a difficult walking and heavier holding of the umbrella.
If by inferentially modifying Caldwell's umbrella (U.S. Pat. No. 100,012) to have a flat brim as shown in full line of FIG. 2, the flat brim may aerodynamically reduce the air resistance on the umbrella hood or crown so that the modified umbrella can be easily carried by a user walking in a storm. Nevertheless, the flat brim of Caldwell's device would not be foldable as shown in the dotted line of FIG. 2 since the rotative folding of the end bow F around a fulcrum P requires a larger radius r1 which however is limited by the small radius r2 near the stretcher link C.
The present inventor has found the drawbacks of a conventional umbrella and invented the present slimly-folded umbrella having extendible brim portion.